The present invention relates to a cooker having high insulating efficiency and capable of boiling and smothering food, and more particularly to a thermal cooker that includes an inner pot having a thermal storage ring connected to an outer bottom surface and an outer pot for receiving the inner pot therein. The inner pot with the thermal storage ring is heated to boil food and juice contained therein and then positioned into the outer pot, so that food and juice in the inner pot is kept boiling with heat released from the thermal storage ring and then be smothered for a period time.
It is a common cooking manner in Chinese food preparation to boil food in a pot or saucepan and then simmer the food gently to produce a delicious dish. A disadvantage of this type of cooking manner is it takes a lot of time and thermal energy to cook. To reduce the time and thermal energy needed in cooking food, there is a thermal cooker developed and available in the market. FIG. 4 is a schematic sectional view of the currently available thermal cooker A. As shown, the thermal cooker A includes an outer pot A1 containing insulating material, such as polylone, foamed plastics, etc., and an inner pot A2 adapted to be positioned in the outer pot and closed with an inner lid. Food is first boiled in the inner pot A2. The inner pot A2 with the boiled food is then positioned into the outer pot A1 that is in turn closed with an outer lid, so that food in the inner pot A2 is kept smothered in the thermal cooked for a period of time with the heat in the boiled food without using other external heat source. Thermal energy needed to cook food is therefore reduced. However, such conventional thermal cooker does not boil food but only smother food that has been previously boiled outside the thermal cooker, and boiled food smothered in the thermal cooker usually does not taste perfectly.